Whenever I feel like buying a mixture, I buy from Ron Carmichael. He tells you exactly what the mixture is composed of and many times has scans of the actual lot you are buying. His prices are all over the place, but I've never been disappointed in one of his mixtures.
http://stores.ebay.com/roncarmichae...047675.l2563For example, if you're looking for a worldwide mixture, in a lot of 2,000 stamps priced at $30, the description is as follows:
there are about 2,000 stamps here (there could be more or less than this)
there is everything of all ages here, while the highlights pictures tend to show modern stuff there is all ages material here
there are large and small stamps, see statistics below
while the vast majority is off paper, there is a wee bit of material on paper in this mixture
because the source is European, there are a lot of European stamps here, especially Germany, check the statistics below
as with any mixture:
there will be duplication, significant in some issues!
there will be mixed condition
Do take time to look at the pictures!
For the statistically minded, samples yielded: (note that because of the level of detail these % are pretty specific, please just use them as a guideline so you have an idea of the relative % of the various aspects of this mixture)
about 33% commemoratives
about 28% mint or postally used
about 12% Germany
about 16% other countries
about 5% CTO (eastern european, trucials etc)
about 67% definitives
about 64% mint or postally used
about 17% Germany
about 47% other countries
about 3% CTO (eastern european, trucials etc)
Yes, the more you pay, the better the stamps will be. Depending on what you're interested in, some sellers offer mixtures of only commemorative stamps.